d and f Block Elements
Position in Periodic Table and Properties
Position in the Periodic Table
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Their position is in between s- and p- block elements.
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There are four rows of transition elements − 3d, 4d, 5d, and 6d. The fourth row of 6d is still incomplete.
Electronic Configuration
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General outer electronic configuration is (n −1)d1−10 ns1−2.
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But this generalization has several exceptions as there is very little difference in energy between (n − 1)d and ns orbitals. For example, Cr has electronic configuration 3d5 4s1 instead of 3d4 4s2. Cu has electronic configuration 3d10 4s1 instead of 3d9 4s2.
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Outer electronic configurations of the transition elements in the ground state are listed in the following tables:
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1st series
2nd series
Element
Atomic number
Outer electronic configuration
Element
Atomic number
Outer electronic configuration
Sc
21
3d14s2
Y
39
4d15s2
Ti
22
3d24s2
Zr
40
4d25s2
V
23
3d34s2
Nb
41
4d45s1
Cr
24
3d54s1
…
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